On Saturday, Mar 29, 2003, at 07:52 US/Pacific, Raymond Camden wrote:
> It is true. If in parent.cfc, outside the methods or in a method but
> not
> var scoped or attribute scoped, if you do x=1, then child.cfc can
> access
> it as well.
Let's try some real code here because I think some folks have gotten
confused:
parent.cfc:
<cfcomponent displayname="parent">
<cfset instance = structNew()>
<cfset instance.x = "Parent X">
<cffunction name="parentMethod" returntype="string">
<cfreturn this.myChild.getInstanceX()>
</cffunction>
</cfcomponent>
child.cfc:
<cfcomponent displayname="child">
<cffunction name="getInstanceX" returntype="string">
<cfdump var="#instance#">
<cfreturn instance.x>
</cffunction>
</cfcomponent>
pc.cfm:
<cfoutput>
<cfset p = createObject("component","parent")>
<cfset c = createObject("component","child")>
<cfset p.myChild = c>
<cfset instance = structNew()>
<cfset instance.x = "The Calling Page X">
#p.parentMethod()#
</cfoutput>
Now, *if* child (composition) objects can access their parent
(enclosing) objects' non-public variables, this should dump an
'instance' struct containing 'x' and print "Parent X". Which it doesn't
because a child (composition) object *cannot* see any of the enclosing
object's data.
Run it - it says "Variable INSTANCE is undefined." inside child.cfc.
Hope that clarifies?
If we were talking about inheritance then, yes, the derived object has
access to all of the base object's data - because CFML has only a
public scope ("this") and a protected scope (unnamed).
Sean A Corfield -- http://www.corfield.org/blog/
"If you're not annoying somebody, you're not really alive."
-- Margaret Atwood
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